Russia isn't often thought of as a country of immigration. Yet the country's enormous territory and shrinking indigenous population invite a striking number of immigrants: Last year, despite the collapse of oil prices and the Ukraine crisis, Russia was the biggest originator of migrant workers' remittances in Europe.

When President Barack Obama said in an interview last year that "immigrants aren’t rushing to Moscow in search of opportunity," commentators with a less gloomy view, and perhaps a bit more knowledge, rushed to point out that, according to a 2013 United Nations report, Russia had the world's second biggest migrant population after the U.S. I wouldn't put much stock in that statement, and not just because the U.S., with more than twice Russia's population, had four times as many immigrants. The UN report also showed Russia's migrant stock barely increased from 1990 to 2013, even though the collapse of the Soviet Union caused many ethnic Russians to leave breakaway republics.

As a Muscovite, I was accustomed to workers from Tajikistan cleaning my yard and Uzbek cooks and waiters in restaurants. Nannies were from Ukraine and Moldova. The contractor who renovated my mom's apartment was from Georgia. They were all there looking for opportunity, as the remittance flows show:

International Fund for Agricultural Development

The 2014 data from the International Fund for Agricultural Development are stunning in two respects. First, Russia ranks highest, with $20.7 billion in remittances, even though its per capita gross domestic product is less than those of other nations. The U.K., which recorded $17.1 billion in remittances, has per capita GDP that is almost 50 percent higher. The second surprise is that last year's economic woes didn't strip Russia of its leadership. Anecdotal evidence suggested that many immigrants from Central Asia and the poorer ex-Soviet nations in Europe and the Caucasus have been going home, but many evidently stuck around. In November 2014, the latest month for which official data are available -- and when the Russian ruble began its freefall -- net immigration, at 23,754 people, was higher than the 2013 monthly average.

So Russia still needs immigrants. And it will need more of them. In the first quarter of this year, the natural decline of Russia's population (the difference between the number of deaths and births) reached 34,584 people, 13 percent more than in the first three months of 2014. There simply aren't enough Russians to do the mostly menial jobs that migrants do.

Another reason why the remittances from Russia are so high is that its strong tech sector has driven down the cost of transfers. The average cost of sending money home was 7.3 percent last year in Europe's wealthier nations, according to IFAD. In Russia, it was just 2.4 percent.

Russia's immigrant laborers often have to put up with awful living and working conditions, as well as racism. The bribe-extorting bureaucracy treats them poorly, and even opponents of President Vladimir Putin such as anti-corruption crusader Alexei Navalny often take anti-immigrant positions. Yet the abundance of low-paid work, the cheapness and ease of sending money home, large diasporas and the widespread knowledge of Russian in the former Soviet nations make Russia attractive. Even the pervasive corruption plays a role: There are more ways to avoid deportation than there would be in any Western European country.

Of course, many of the migrants tend to come and go. And in general, they aren't likely to be the doctors, programmers and other white-collar workers who are welcomed to the U.S. and developed Europe. Still, their efforts help keep their home countries afloat. Ukraine has 4.4 million migrant workers in the rest of Europe, most of them in Russia, according to IFAD. It receives $7.6 billion a year in remittances from them. Belarus, Moldova, Tajikistan and Uzbekistan are all dependent on the money their citizens send home from Russia.

It's in Western Europe's interest to keep it this way. If Russia's economy goes into a tailspin and the migrant workers begin to face unbearable hardship, they will look for opportunity elsewhere. For some Central Asian Muslims, this will mean the Middle East; for the people of Ukraine, Belarus, Moldova and the Caucasus, the European Union is likely to be the new destination.

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